A remote supervisory control system has conventionally been realized and managed, which connects a plurality of elevating machines to a remote supervisory center installed in a place remote therefrom via a general public line, comprehensively supervises the states of elevating machines such as elevators and escalators, installed in a specific area, and malfunction information on those elevating machines, and controls them if necessary. In response to recent increases in the speed and capacity of general public lines, high-speed digital networks for realizing the Internet and the like have been widely set up in addition to conventional analog lines, using existing phone lines. This has made it possible to perform high-speed, real-time transmission of image information and audio information. On the other hand, since open networks such as the Internet can be accessed by the general public, the necessity to consider security functions for information has been growing further.
Under such circumstances, some proposals have been made as to conventional remote supervisory control systems for elevating machines. For example, JP 6-156907 A proposes the idea of connecting a control apparatus, a camera within a car, and an interphone to a remote supervisory device via a high-speed digital communication line and simultaneously transmitting control signals, audio signals, and image signals. This enables high-speed transmission of a large quantity of information such as images and sounds. Further, according to JP2003-89481A, the phone number of a service information center is stored in a terminal device on an elevator side. In the event of a call, it is determined whether or not a calling number is a predetermined one. A response is made only when those numbers coincide with each other. This is supposed to prevent strangers from plotting malicious mischief or obstructive operation.
However, since the conventional remote supervisory control systems for elevating machines are configured as described above, there is a fear that any stranger from the general public may be able to access control information on the elevating machines as well because of, for example, the use of a general high-speed digital line. Further, collation based solely on phone numbers allows any stranger from the general public to access the information once he or she knows the phone number of the service information center. Thus, there is a fear that this stranger will perform an invalid operation on the elevating machine.
It is an object of the present invention to realize a remote supervisory control system for an elevating machine, which enables reliable communication with an enhanced security function through collation with a predetermined specific code by means of an ordinary line as to a control command for an elevating machine, while making it possible to perform high-speed, large-capacity communication by means of a general high-speed digital network as to state information, image information, and audio information on the elevating machine.